let a, b, x0 be Real; for n being non zero Element of NAT
for f being PartFunc of REAL,(REAL-NS n) st a <= b & f is_integrable_on ['a,b'] & f | ['a,b'] is bounded & ['a,b'] c= dom f & x0 in ].a,b.[ & f is_continuous_in x0 holds
ex F being PartFunc of REAL,(REAL-NS n) st
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) & F is_differentiable_in x0 & diff (F,x0) = f /. x0 )
let n be non zero Element of NAT ; for f being PartFunc of REAL,(REAL-NS n) st a <= b & f is_integrable_on ['a,b'] & f | ['a,b'] is bounded & ['a,b'] c= dom f & x0 in ].a,b.[ & f is_continuous_in x0 holds
ex F being PartFunc of REAL,(REAL-NS n) st
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) & F is_differentiable_in x0 & diff (F,x0) = f /. x0 )
let f be PartFunc of REAL,(REAL-NS n); ( a <= b & f is_integrable_on ['a,b'] & f | ['a,b'] is bounded & ['a,b'] c= dom f & x0 in ].a,b.[ & f is_continuous_in x0 implies ex F being PartFunc of REAL,(REAL-NS n) st
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) & F is_differentiable_in x0 & diff (F,x0) = f /. x0 ) )
consider F being PartFunc of REAL,(REAL-NS n) such that
A1:
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) )
by Lm18;
assume
( a <= b & f is_integrable_on ['a,b'] & f | ['a,b'] is bounded & ['a,b'] c= dom f & x0 in ].a,b.[ & f is_continuous_in x0 )
; ex F being PartFunc of REAL,(REAL-NS n) st
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) & F is_differentiable_in x0 & diff (F,x0) = f /. x0 )
then
( F is_differentiable_in x0 & diff (F,x0) = f /. x0 )
by A1, Th55;
hence
ex F being PartFunc of REAL,(REAL-NS n) st
( ].a,b.[ c= dom F & ( for x being Real st x in ].a,b.[ holds
F . x = integral (f,a,x) ) & F is_differentiable_in x0 & diff (F,x0) = f /. x0 )
by A1; verum